1. Field of the Invention
The present invention relates to a method of producing an optical module, in particular, a method of producing a coherent optical module.
2. Background Arts
An international patent application published as WO2011/027895 has disclosed an optical de-modulator of a type of the planar light wave circuit (PLC) and an optical transmission system implementing the PLC de-modulator. The PLC modulator disclosed therein receives a coherent optical signal that multiplexes two optical signals each having a polarization plane different from each other and modulated by phases of light. An optical module implementing such devices and additional optical components like a mirror and/or a beam splitter (BS), the optical components are sometimes necessary to be precisely aligned with respect to a housing installing them.